Endoscopes are well known devices for visually inspecting inaccessible places such as human body cavities. Typically, the endoscope comprises an elongated insertion tube with a handle at the proximal end as seen from the operator and visual inspections means, such as a built in camera, at the distal end of the elongated insertion tube. Electrical wiring for the camera and other electronics such as LED lighting run along the inside of the elongated insertion tube from the handle to the tip at the distal end. Instead of using cameras, endoscopes may also be fibre-optic, in which case the optical fibres run along inside of the elongated insertion tube.
In order to be able to manoeuvre the endoscope inside the body cavity, the distal end of the endoscope may comprise a section with increased flexibility, e.g. an articulated tip part allowing the operator to bend this section. Typically this is done by tensioning or slacking pull wires also running along the inside of the elongated insertion tube from the articulated tip part to a control mechanism of the handle. Furthermore, a working channel may run along the inside of the insertion tube from the handle to the tip, e.g. allowing liquid to be removed from the body cavity or allowing the insertion of surgical instruments or the like into the body cavity.
U.S. Pat. No. 4,911,148 discloses a fibre-optic endoscope with an articulated tip part. The articulated tip part is an integrally moulded member with cut-out progressively increasing in size towards the distal end. The cut-outs are provided in one side only, thus only allowing the bending of the articulated tip in one direction. The articulated tip comprises a central working channel. The pull wire and the fibre-optic cables are located in lumens arranged in the wall part of the articulated tip part.
US-A-2004/0199052 discloses a camera endoscope with an articulated tip part. The articulated tip comprises a central lumen. Though not clearly described, a working channel appears to be arranged in this central lumen. All cables except the pull wires are also arranged in this central lumen. The pull wires are located in lumens arranged in the wall part of the articulated tip part.
U.S. Pat. No. 4,580,551 discloses an articulated tip part for a fibre-optic endoscope. The cross-section of the articulated tip part comprises several lumens. In one of the lumens a tube for air or water is provided. This tube is comparatively narrow and will not be able to serve as a working channel as such.